Caption: MODEL RELEASED. Spinal decompression surgery. Image 2 of 6. Surgeon preparing to make the first incision in order to operate on a patient's spine. This patient has spinal stenosis, where a narrowing of the spinal canal has put pressure on the spinal cord. This is usually due to the natural spinal degeneration that occurs with aging. It can also be caused by the displacement of the vertebrae, osteoporosis or a tumour. The surgery will remove parts of the lumbar vertebrae in order to relieve the pressure (decompression).